Even so the tongue is a little member, and boasteth great things.
Behold, how great a matter a little fire kindleth!
And the tongue is a fire, a world of iniquity: so is the tongue
among our members, that it defileth the whole body, and setteth
on fire the course of nature; and it is set on fire of hell.
- Bible, James (ch. III, v. 5-6)

If thine enemy be hungry, give him bread to eat; and if he be
thirsty, give him water to drink.
For thou shalt heap coals of fire upon his head, and the Lord
shall reward thee.
- Bible, Proverbs (ch. XXV, v. 21-22)